Combination lock controlled electrical instrumentality



Sept. 22, 1970 A. M. FISH 3,529,454

COMBINATION LOCK CONTROLLED ELECTRICAL INSTRUMENTALITY Filed Jan. 31, 1968 2 Sheets-Sheet 1 A 5 1 35% v arqn r 1s Se t. 22, 1970 A. M. FISH 3,529,454

I COMBINATION LOCK CONTROLLED ELECTRICAL INSTRUMENTALITY Filed Jan. 51, 1968 r 2 Sheets-Sheet 2 Asran -Fzsh United States Patent ABSTRACT OF THE DISCLOSURE An electrical instrumentality, such as a solenoid operated lock bolt for a door or an electric motor for a machine tool, is controllable from a remote station by actu ation of a control member that can be operated only upon decoding of a combination lock by an authorized person.

This invention relates to a code controlled locking device the primary objective of which is high security coupled with unlocking convenience.

More particularly, it is a purpose of this invention to provide a locking device wherein unlocking is effected by actuation of an electric switch at the dictate of a manually movable control member that can be operated only upon proper decoding of a combination lock mechanism by an authorized person.

By way of example, a locking device of this invention can comprise an electromagnetic door latch the solenoid of which is energizable to retract the latch bolt and free the door for opening only after the combination of the lock has been decoded to make possible actuation by the control member of an electric switch governing the energizing circuit for the solenoid.

In this sense, the code controlled locking mechanism of this invention governs operation of an electrical instrumentality in the nature of a solenoid. It is also a purpose of the invention, however, to provide a code controlled locking mechanism which can be used to govern any of a number of electrical instrumentalities, as for example the starting and stopping of the motors of complicated and costly machine tools that could be damaged if untimely started up by unauthorized personnel not aware of the danger of so doing.

With these observations and objects in mind, the manner in which the invention achieves its purpose will be appreciated from the following description and the accompanying drawings. This disclosure is intended merely to exemplify the invention.

The drawings illustrate two complete examples of the physical embodiment of the invention constructed according to the best modes so far devised for the practical application of the principles thereof, and in which:

FIG. 1 is a fragmentary elevational view of a code controlled locking mechanism of this invention, illustrating how it can be employed to govern energization of an electromagnetic door latch;

FIG. 2 is a longitudinal sectional view through the locking mechanism, taken on the plane of the line 22 in FIG. 1

FIG. 3 is an elevational view looking into the rear of the housing for the mechanism, with the mounting plate therefor removed;

FIG. 4 is a rear fragmentary view of the mechanis illustrating a modification thereof; and

FIG. 5 is a wiring diagram illustrating one use for the embodiment of the invention seen in FIG. 4.

Referring now to the accompanying drawings, the numeral 10 designates a door which can be locked closed by an electromagnetic latch 11 which includes a normalice 1y projected lock bolt 12 and a solenoid 13 that must be energized to retract the lock bolt and free the door for opening.

According to this invention, the electromagnetic latch 11 is governed by a code controlled locking device 14 that can be mounted on a wall at a station near to the door as shown, or at some distance from the door if desired. For example, the door 10 can be the lock controlled inner door of a vestibule, such as found in apartments and the like, having an outer door (not shown) that is normally unlocked. In such instances, the locking device 14 could be mounted on a wall of the vestibule remote from the door 10.

The locking device 14 comprises an elongated upright housing or enclosure 15 containing a combination lock mechanism 16, a normally open electric switch 17 mounted in an upper portion of the housing for controlling energization of the solenoid 13, and control means 18 in the lower portion of the housing having an externally accessible knob 19 which can be rotated in one direction from a neutral position to effect closure of the switch and energization of the solenoid 13 to retract the lock bolt 12. The combination lock mechanism 16 normally prevents the knob from being actuated in the direction of the arrow 20 to actuate the switch 17, and it permits such actuation of the knob only after a number of push buttons 21 constituting decoding means have been depressed in a predetermined sequence by an authorized person having knowledge of the correct decoding combination.

Rotary movement of the control knob 19 in the direction of the arrow 20 is translated into closing actuation of the switch 17 through a switch actuating member 22 in the housing in the form of an elongated flat bar which extends lengthwise between the control means 18 and a contactor button 23 on the switch. The lower end of the switch actuating member 22 is eccentIically pivotally connected as at 24 to a disc 25 that is fixed to the inner end of a shaft 26. This shaft projects forwardly through the front wall 27 of the housing to have the control knob 19 afiixed to its outer end.

The pivotal connection between the disc 25 and the actuating bar 22 provides a support for the lower end of the bar. A portion of the bar intermediate its ends is flatwise slidingly supported on the rear end of a post 28 fixed to the front wall of the housing, a washer 29 being interposed between the post and the bar as seen best in FIG. 2. The rear end portion of the post is internally threaded to receive a screw 30, which projects through a lengthwise extending slot 31 in the bar to retain the same on the post. A washer 32 is preferably interposed between the bar and the head of the screw, so that the bar will be freely slidable between the two washers 29 and 32.

The pivot connection 24 between the lower end of the switch actuating bar and the disc 25 is located a distance to one side of the disc axis when the control means is in its neutral position shown, and to which it is yieldingly biased by a double acting torsion spring 34 encircling the shaft 26 and having downwardly divergent arms 35 and 36 each of which passes under a pair of abutments 37 and 38 on the disc 25 and a plate 39, respectively. The plate 39 is secured to the housing in spaced parallel relation to the front wall 27 thereof as by a pair of screws 40 threaded into the rear portions of posts 41 that are fixed to the front wall and project rearwardly therefrom at opposite sides of the shaft 26.

The upper end of the switch actuating bar 22 is bent over to provide a foot 43 which is normally spaced a distance from the contactor button 23 of the electric switch 17. The foot is carried into engagement with the contactor button to close the switch in consequence of rotary movement of the disc 25 in the counterclockwise direction as seen in FIG. 3. Such rotary movement is imparted to the disc by the control knob 19 at the front of the housing, during clockwise rotary movement of the knob as seen in FIG. 1.

The combination locking mechanism 16 illustrated in the drawing is a commercially available type known as a Simplex push button mechanism that can be preset by combination change mechanism having a reset button 44, so as to respond to any one of over one thousand different combinations when provided with five push buttons 21, as shown. In other words, the lock mechanism can be decoded to free the control knob for actuation of the switch 17 only upon depression of a preselected number of the push buttons in a preset order or sequence.

The working parts of the combination lock mechanism are contained in a small elongated casing 45 fixedly mounted in an upright position in the housing 15 close to its front wall 27, between the latter and the switch actuating member 22, and with the reset button 44 adjacent to a hole 46 in the front wall. Mounting ears 47 at opposite ends of the casing 45 rest upon upper and lower bosses 48 fixed to the front wall of the housing. A screw 49 secures the lower ear to its boss, while the upper ear is secured to its boss by the post 28, which has its forward end threaded into the upper boss 48. In this respect, it should be noted that the same post 28 that supports the switch actuating member 22 also secures one end of the casing 45 to the housing.

The electric switch 17 in the upper portion of the housing is mounted upon the horizontal leg of an angle shaped bracket 50 having a vertical leg that is secured by screws 51 to laterally spaced bosses 52 on the inside of the front housing wall. It is one of the features of this invention that the switch 17 can be provided with time delay means indicated at 53 which is adjustable by a knob 54 to maintain the switch closed for a preselected period of time following closure thereof by the actuating member 22. For example, if the locking device 14 is located in the vestibule of an apartment building at a station remote from the inner door thereof, the knob can be adjusted to maintain the switch 17 closed and the latch bolt 12 retracted for a period of time adequate to allow a person to walk over to the door 10 and open the same after he has properly decoded the combination locking mechanism and rotated the control knob in the switch actuating direction. A time delay period of from five to ten seconds should ordinarily sufiice for that purpose.

As seen best in FIG. 2, the housing comprises cooperating front and rear housing sections. The rear housing section consists of a flat mounting plate 56 having opposite longitudinal side edges that abuttingly engage the rear edges of the side walls 57 of the front housing section. Inturned top and bottom flanges 58 on the mounting plate fit inside the end walls of the front housing section and properly locate the same relative to the mounting plate. Screws 60 that pass through suitable holes in the mounting plate are provided to hold the same fiatwise in position upon a wall surface 61. If the wall surface 61 is the outer surface of a wall stud, a rear portion of the front housing section can be recessed within the wall as shown in FIG. 2.

The hole 46 in the front housing wall 27 is noncircular and aligns with a stud 63 that is fixed to the mounting plate and extends forwardly therefrom nearly to the front wall of the housing. The casing 64 of a key operable cylinder lock mechanism is nonrotatably but axially slidably received in the hole 46 and has an enlarged head 65 that engages the exterior of the front wall 27 of the housing. The cylinder 66 of the lock is freely rotatable in the casing by a proper key 67 inserted into the cylinder, and the latter has a coaxial screw threaded connection with the stud 63 so that the cylinder can be screwed onto the stud to thereby draw the front housing section down onto the mounting plae and hold the two housing sections properly assembled. It will be understood, of course, that the cylinder has the usual enlarged head that fits and bottoms in a counterbore in the front of the housing, to enable the connection between the cylinder and the stud 63 to hold the lock casing in place on the front housing section and to hold the two housing sections properly assembled.

It is significant to note that the cylinder lock mechanism can be removed from its hole 46 when the cylinder is backed off of its stud by a key in position in the cylinder. The hole 46 then provides access to the combination change button 44, to enable the combination to be reset without necessarily removing the front housing sec tion from the mounting plate 56.

The code controlled locking device described can be a great convenience especially for persons who frequently are burdened with bags of groceries or other packages in that it not only allows opening of the door controlled thereby without a key but requires only one hand for de coding of the lock mechanism and for opening of the door. This is ordinarily a two handed operation when the door must be unlocked by a key to retract a latch bolt that is biased to its locking position.

It will be apparent that the locking device of this invention can be used to considerable advantage in other ways than described above. Another such use is disclosed in FIGS. 4 and 5, where the locking device of this invention is employed to control the starting of an electric motor 70. The motor, for example, can be the prime mover of a complicated and costly machine tool which should not be started up by unauthorized personnel especially if the machine tool itself or a work piece thereon might thereby suffer damage.

As seen in FIG. 5, the electric switch 17 in the locking device 14 can be wired in the energizing circuit for the solenoid 71 of an electromagnetic switch 72 governing operation of the motor. The electromagnetic starting switch 72 has two sets of normally open contacts 73 and 74 which are bridged when the solenoid 71 is energized. Bridging of the contacts 73 completes an energizing circuit for the motor 70, while bridging of the contacts 74 completes a holding circuit for the solenoid 71 to maintain the switch closed. As is obvious, the holding circuit leads through a normally closed switch 75 which can be momentarily manually opened to effect deenergization of the solenoid 71 and stopping of the motor.

It will be appreciated, of course, that the circuitry shown in FIG. 5 does not require the switch 17 to be held closed by its time delay means 53. Consequently, the adjusting knob 54 of the time delay means can be set to either eliminate the time delay feature or to produce an extremely short time delay period during which the switch 17 will remain closed following actuation thereof by the control knob 19 and actuating bar 22 connected therewith.

If desired, the electric switch 75 governing the holding circuit for the solenoid 71 can be mounted on the lower portion of the housing 15 of the locking device 14, and actuated to open position in consequence of rotary movement of the control knob 19 in the counterclockwise direction as seen in FIG. 1. The switch 75 shown in FIG. 4 is of the same type as the switch 17, and it is mounted on a bracket 76 in a position such that its contactor button 77 will be engaged and depressed by the bottom end 78 of the switch actuating bar 22 when the disc 25 to which it is connected is rotated in the clockwise direction as seen in FIG. 4, by the control knob 19.

In the Simplex combination locking mechanism shown the control knob 19 is at all times free to turn in the counterclockwise direction (FIG. 1) to effect scrambling of the combination. Consequently, the stop switch 75 can be opened at any time by such turning of the control knob in the combination scrambling direction. As explained before, however, the switch 17 can be actuated to its closed position only after an authorized person has properly decoded the locking mechanism by means of its push buttons 21.

There may be times when it is also desirable to take advantage of the time delay feature of the switch 75, as for example to delay restarting of the motor 70 for a minute or so after it has been stopped by opening of that switch. The adjusting knob 54 on the switch, of course, is provided for that purpose.

The switch 75 may also be used to advantage when the electrical control instrumentality controlled by the locking device of this invention is a solenoid operated latch mechanism for a door, such as described earlier. In that case, the switch 75 would be connected in series with the switch 17 in the manner seen in FIG. 5, where the solenoid 71 can be compared to that provided in an electromagnetic door latch mechanism. Opening of the switch 75 could then eifect deenergization of the latch solenoid and projection of the lock bolt to its door locking position if for any reason the person having decoded the lock mechanism and actuated the switch 17 decided against opening of the door 10.

From the foregoing description, together with the accompanying drawings, it will be apparent that this invention provides a code controlled locking device which features unlocking convenience without the use of a key and without sacrificing security.

What is claimed as my invention is:

1. In combination with a door and a normally projected solenoid operated lock bolt which is retractable in consequence of energization of the solenoid to free the door for opening:

(A) a housing which can be mounted at a location remote from the door;

(B) a combination lock mechanism in the housing having a movable control member which is yieldingly biased to a normal position and which is actuatable in one direction from the exterior of the housing against said bias thereon, said mechanism having manually actuatable decoding means accessible from the exterior of the housing and which must be manipulated in a predetermined decoding sequence in order to free the control member for movement in said direction;

(C) a normally open switch in the housing adapted when closed to effect energization of said solenoid;

(D) switch actuating means in the housing connected to and movable with the control member to effect closure of the switch in consequence of movement of the control member in said direction from its normal position;

(E) and time delay means associated with said switch for delaying opening thereof for a predetermined interval following closure thereof by the switch actuating means despite return of the control member to its normal position, whereby a person who has decoded the lock mechanism and actuated the control member will have ample time to reach and open the door before the solenoid is deenergized.

2. The combination of claim 1, further characterized by:

(A) a normally closed switch in the housing in series with said normally open switch;

(B) said control member being movable at all times in the opposite direction from its normal position, against said bias thereon;

(C) and a switch actuating member in the housing connected to and movable with said control member to effect opening of said normally closed switch in consequence of movement of the control member in said opposite direction from its normal position.

3. The combination of claim 2, further characterized by time delay means associated with said normally closed switch to delay reclosing thereof for an interval following opening thereof comparable in time to the interval required for said normally open switch to reopen.

4. A code controlled mechanism for governing operation of an electrical instrumentality, comprising:

(A) a housing;

(B) a manually movable switch actuating member in the housing;

(C) means in the housing supporting the switch actuating member for movement in opposite directions out of a neutral position;

(D) yieldable biasing means acting upon said member to define its neutral position and to return the same to neutral from positions displaced in either direction therefrom;

(E) operating means connected with the switch actuating member and having a portion accessible at the exterior of the housing to provide for imparting movement to said member;

(F) a combination lock mechanism in the housing operatively connected with said member to normally block motion thereof in one direction from neutral without interfering with movement of said member in the opposite direction from neutral, said mechanism having manually actuatable decoding means accessible from the exterior of the housing and which must be manipulated in a predetermined sequence in order to free the switch actuating member for movement in said one direction from neutral;

(G) an electric switch in the housing to control energization of said electrical instrumentality, and actuatable by said member in consequence of movement thereof in said one direction from neutral;

(H) said operating means comprising a part in the housing supported thereby for rotation in opposite directions about a fixed axis remote from said switch;

(I) said switch actuating member comprising an elongated bar having one end portion pivotally connected to said part a distance outwardly from the axis thereof, and having its other end portion adjacent to the switch;

(J and said supporting means comprising (1) an elongated slot in an intermediate portion of the bar,

(2) and means fixed to the housing and extending into said slot to constrain the bar to substantially endwise motion in consequence of rotary movement of said part.

5. In combination with a door and a normally projected solenoid operated lock bolt which is retractable in consequence of energization of the solenoid to free the door for opening:

(A) a housing which can be mounted at a station remote from the door;

(B) a combination lock mechanism in the housing having (1) decoding means accessible for manual actuation from the exterior of the housing;

(2) and movable control means yieldingly biased to a neutral position from which it is at all times free to be moved in one direction to effect scrambling of the combination, said control means having a portion acecssible for operation from the exterior of the housing and being movable in opposite direction out of neutral only upon manipulation of the decoding means in a predetermined sequence;

(C) a normally open electric switch mounted in the housing and adapted when closed to effect energization of said solenoid;

(D) switch actuating means in the housing operatively connected with said control means to move therewith and operable to effect closure of the switch in consequence of movement of the control means in said opposite direction out of neutral;

(B) said housing comprising cooperating front and rear housing sections providing spaced apart opposin front and rear housing walls;

(F) means on the rear housing section providing for securement thereof to a surface on a wall;

(G) said front wall having a non-circular hole there- (H) a stud in the housing fixed to said rear wall thereof nd extending forwardly in line with said hole;

(I) and a key operable lock mechanism detachably securing said housing sections together, and comprising (1) a casing removably but non-rotatably received in said hole and having a head engaging the exterior of said front wall,

(2) a cylinder freely rotatable in said casing upon insertion of a proper key into the cylinder,

(3) and a screw threaded connection between the cylinder and said stud by which the casing is held in place in said hole and the cylinder can be backed off of the stud when rotated by its key, to free the front housing section for removal from the rear section.

6. In combination with a door and a normally projected solenoid operated lock bolt which is retractable in consequence of energization of the solenoid to free the door for opening:

(A) a housing which can be mounted at a station remote from the door;

(B) a combination lock mechanism in the housing having 1) decoding means accessible for manual actution from the exterior of the housing;

(2) and movable control means yieldingly biased to a neutral position from which it is at all times free to be moved in one direction to effect scrambling of the combination, said control means having a portion accessible for operation from the exterior of the housing and being movable in the opposite direction out of neutral only upon manipulation of the decoding means in a predetermined sequence;

(C) a normally open electric switch mounted in the housing and adapted when closed to effect energization of said solenoid;

(D) switch actuating means in the housing operatively connected with said control means to move therewith and operable to effect closure of the switch in consequence of movement of the control means in said opposite direction out of neutral;

(E) said housing having an exterior wall with an aperture therein to provide access to the interior of the housing;

(F) said combination lock mechanism having combination change means including a movable member which must be manually actuated in order to change the combination;

(G) means mounting the combination lock mechanism in the housing with said movable member of the combination change means adjacent to said aperture;

(H) a key operable lock mechanism removably received in said aperture to close the same, and comprising (1) a casing having a head engaging portion of said exterior wall around the aperture therein,

(2) and a cylinder freely rotatable in the casing upon insertion of a proper key into the cylinder;

(I) and screw means fixed in the housing and having a threaded connection with the cylinder by which the casing is held in place in said aperture and the cylinder can be backed off of said screw means when rotated by its key, to free the casing for removal from said aperture and thereby provide access to said movable combination change member.

7. A code controlled mechanism for governing the energizing circuit of an electrical instrumentality, characterized by:

(A) a combination lock mechanism having manually actuatable decoding means;

(B) a manually actuatable knob governed by the combination lock mechanism and movable in one direc tion out of a normal position only after manipulation of the decoding means in a predetermined fashion, said knob being yieldingly biased against such movement out of its normal position;

(C) a switch actuating member connected with said knob to be moved thereby from a normal position toward another position in consequence of movement of the knob in said one direction from normal;

(D) a normally open electric switch operable when closed to complete the energizing circuit of an electrical instrumentality, said switch being operatively and associated with the switch actuating member so that closure of the switch is effected in consequence of movement of said member toward said other position thereof;

(E) and instrumentalities associated with said switch for maintaining the energizing circuit established by the switch despite opening thereof due to return of the switch actuating member and the knob to their normal positions, said instrumentalities including means other than said switch operable to effect deenergization of said circuit.

8. The code controlled mechanism of claim 7, further characterized by:

(A) said means comprising a normally closed electric switch adapted when opened to effect de-energization of the circuit established by closure of the normally open electric switch;

(B) said knob being at all times movable in the opposite direction out of its normal position;

(C) and means for actuating said normally closed switch to its open position in consequence of movement of the knob in said opposite direction from neutral, to thereby enable an electrical instrumentality rendered operative by closure of said normally open switch to be rendered inoperative without interference from the lock mechanism.

9. The code controlled mechanism of claim 7, wherein said instrumentalities comprise time delay means connected with said normally open switch and operable to prevent opening thereof for a predetermined interval following closure thereof by the switch actuating member despite return of the latter to its normal position.

10. A code controlled mechanism for governing operation of an electrical instrumentality, comprising:

(A) a housing;

(B) a switch actuating member in the housing;

(C) means in the housing supporting the switch actuating member for movement in opposite directions out of a normal position;

(D) an operating knob supported for motion in opposite directions and accessible at the exterior of the housing;

(E) means operatively connecting the knob with the switch actuating member whereby the latter is actuatable out of its normal position to another posi tion in consequence of movement of the knob in one direction;

(F) yieldable biasing means acting upon said member for returning the same to its normal position;

(G) a combination lock mechanism in the housing operatively connected with said member and effective to normally block knob produced motion of said member to its said other position without interfering with movement of the knob in the opposite direction, said mechanism having manually actuatable decoding means accessible from the exterior of the housing and which must be manipulated in a predetermined fashion in order to free the switch actuating member for knob produced motion to its said other position;

(H) and an electric switch in the housing to eifect energization of said electrical instrumentality in consequence of knob produced movement of the switch actuating member toward its said other position.

11. The code controlled mechanism of claim further characterized by:

(A) said switch being of the normally open type and being adapted to be closed by said switch actuating member in consequence of movement thereof in one direction from normal, in order to render the electrical instrumentality operative;

(B) a normally closed switch in the housing adapted when opened to effect de-energization of said electri cal instrumentality;

(C) and means on the switch actuating member for actuating said last named switch to its open position in consequence of knob produced movement of the switch actuating member in the opposite direction, to thereby enable an electrical instrumentality rendered operative by closure of said first named switch to be rendered inoperative without interference from the lock mechanism.

12. The code controlled mechanism of claim 10, further characterized by:

(A) said switch being of the normally open type and being adapted to be engaged and closed by the switch actuating member in consequence of movement thereof in one direction;

(B) and time delay means connected with said switch and operable to prevent opening thereof for a predetermined interval following closure thereof by the switch actuating member despite return thereof to its normal position.

13. In combination with a door and a normally projected solenoid operated lock bolt which is retractable in consequence of energization of the solenoid to free the door for opening:

(A) a housing which can be mounted at a station remote from the door;

(B) a combination lock mechanism in the housing having (1) decoding means accessible for manual actuation from the exterior of the housing,

(2) and movable control means yieldingly biased to a neutral position from which it is at all times free to be moved in one direction to effect scrambling of the combination, said control means having a portion accessible for operation from the exterior of the housing and being movable in the opposite direction out of neutral only upon manipulation of the decoding means in a predetermined sequence;

(C) a normally open electric switch mounted in the housing and adapted when closed to effect energization of said solenoid;

(D) switch actuating means in the housing operatively connected with said control means to move therewith and operable to efi'ect closure of the switch in consequence of movement of the control means in said opposite direction out of neutral;

(E) and time delay means operatively associated with said switch for delaying opening thereof for a predetermined interval of time following closure thereof despite return of the control means to its neutral position, to enable the door to be opened by a person having first properly decoded the lock mechanism at said station remote from the door.

14. A code controlled mechanism for governing operation of an electrical instrumentality such ats an electric motor, comprising:

(A) means providing an enclosure;

(B) a combination lock mechanism mounted in the enclosure and having (I) manually actuatable decoding means accessible from the exterior of the enclosure,

(2) and operating means which is manually actuatable from the exterior of the enclosure in opposite directions against yielding bias tending to hold the same in a neutral position, said operating means being at all times movable in a first direction from neutral to effect scrambling of the combination and being movable in the opposite direction from neutral only upon ac tuation of said decoding means in a predetermined sequence;

(C) an electromagnetic switch to govern operation of the motor;

(D) electric switch means mounted in the housing to control operation of the electromagnetic switch;

(E) mechanism in the housing operable in consequence of movement of said operating means in said opposite direction from neutral for eifecting actuation of the switch means and operation of the electromagnetic switch thereby;

(F) and mechanism in the housing operable in consequence of movement of said operating means in said first direction for effecting actuation of said switch means to render the electromagnetic switch inoperative.

15. The code controlled mechanism of claim 14, further characterized by:

(A) the electromagnetic switch having a solenoid which must be energized in order to effect closure of the electromagnetic switch and operation of the motor thereby;

(B) closure of said electromagnetic switch establishing a holding circuit for the solenoid;

(C) and said electric switch means comprising (1) a normally closed switch connected in said holding circuit and adapted to be opened in consequence of movement of said control means in said first direction from neutral to thereby eifect de-energization of the solenoid,

(2) and a normally open momentary contact switch connected in series with the solenoid to effect energization thereof in consequence of movement of the control member in said opposite direction from neutral.

References Cited UNITED STATES PATENTS 2,855,588 10/1958 Allen 340276 3,128,414 4/ 1964 Miehle 317-134 3,192,448 6/1965 Hevenor 317-134 3,242,708 3/1966 Sanchez 277 3,296,842 1/ 1967 Auerbach et al 7 7082 3,298,210 1/1967 Nyborg 7091 3,353,383 11/1967 Fish 70151 RICHARD E. MOORE, Primary Examiner R. L. WOLFE, Assistant Examiner 

